//Digital pin 7 for reading in the pulse width from the MaxSonar device.
//This variable is a constant because the pin will not change throughout execution of this code.
const int pwPin = 3; 
//variables needed to store values
long pulse, inches, cm;
void setup() {
  //This opens up a serial connection to shoot the results back to the PC console
  Serial.begin(9600);
}
void loop() {
  pinMode(pwPin, INPUT);
    //Used to read in the pulse that is being sent by the MaxSonar device.
  //Pulse Width representation with a scale factor of 147 uS per Inch.

  pulse = pulseIn(pwPin, HIGH);
  //147uS per inch
  inches = pulse/147;
  //change inches to centimetres
  cm = inches * 2.54;
  Serial.print(inches);
  Serial.print("in, ");
  Serial.print(cm);
  Serial.print("cm");
  Serial.println();
  delay(100);
}
